Using the 10-15-25 rule, how do you calculate the available water for a static pressure of 80 PSI with a residual pressure of 73 PSI while flowing 300 gallons?

To determine the available water using the 10-15-25 rule, you first need to understand how static pressure, residual pressure, and flow rate interact to give you a measure of water availability.

The 10-15-25 rule states that for every 10 PSI of available pressure up to 50 PSI, you can flow 100 gallons per minute (GPM) of water. For each additional 15 PSI up to 70 PSI, you can also add 100 GPM. Finally, for every 25 PSI beyond 70 PSI, you add 100 GPM as well.

In this case, you have a static pressure of 80 PSI and a residual pressure of 73 PSI. The difference between the static and residual pressures gives you an indicator of the available pressure for flow calculations. Here, the available pressure is calculated as 80 PSI (static) - 73 PSI (residual) = 7 PSI.

According to the 10-15-25 rule, since you have 7 PSI of available pressure, this falls into the first category (up to 10 PSI) which allows you to flow 100 GPM. Therefore, if you calculate the total available water for 300 gallons flowing at that